FLUIDIC CIRCUIT FOR UNIFORM, HIGH VELOCITY SPRAY ACROSS A RANGE OF OPERATING TEMPERATURES
A fluidic geometry to produce uniform oscillating sprays is described. The geometry can be embodied as an insert, housing, or system in which an inlet feeds an interaction chamber. A major island is disposed at the upstream end of that chamber so as to create two power nozzles that are positioned off of the centerline axis and downstream of the major island. A minor island is also disposed within the interaction chamber, but remains spaced apart and downstream of the major island so as to define an exchange channel. The exchange channel creates an inertance effect that can be controlled and adjusted so as to provide the desired oscillating spray fan produced by the geometry. This arrangement exhibits consistent cold and high temperature performance for a range of fluid compositions and operating conditions.
1 . A fluid insert for producing an oscillating spray pattern at low temperatures, the insert comprising:
a body defining an inlet positioned within an upper portion of the body and an outlet positioned at a lower edge the body so that fluid flows in a common spatial plane along a major facing of the body from the inlet to the outlet;
a major island and a minor island each formed symmetrically on the major facing around a centerline axis of the body and wherein the major island: i) is positioned closer to the inlet in comparison to the minor island, ii) includes a lower edge that is spaced apart from an upper edge of the minor island so as to define an exchange channel, and iii) has a larger maximum transverse width in comparison to the minor island;
an interaction chamber positioned between the inlet and the outlet and having: i) an upper facing defined by a lower edge of the minor island, and ii) a lower facing including a pair of straight edge wall sections emanating in opposite directions from an opening defining the outlet, extending perpendicular to the centerline axis for a wall distance, and thereafter curving axially upward to define opposing protuberances; and
opposing power nozzles defined by the opposing protuberances and opposing transverse ends of the major island; and
wherein the power nozzles each direct a fluid jet toward opposing transverse ends of the minor island.
2 . The fluidic insert of claim 1 wherein the minor island is a crescent, a C-shape, or a speed bump-shape.
3 . The fluidic insert of claim 1 wherein the opposing transverse ends of the minor island include thickened portions to impart a serif-style C-shape.
4 . The fluidic insert of claim 1 wherein the lower edge of the major island is spaced apart from the upper edge of the minor island at a substantially constant distance along all of the exchange channel.
5 . The fluidic insert of claim 1 wherein the interaction chamber has a reverse mushroom configuration.
6 . The fluidic insert of claim 1 wherein the wall distance is equal to or up to three times greater than an outlet distance defined by a narrowest point between the pair of straight edge wall sections defining the outlet.
7 . The fluidic insert of claim 1 wherein the opposing transverse ends of the major island are positioned axially closer to the lower edge of the body in comparison to the opposing protuberances.
8 . The fluidic insert of claim 1 wherein a power nozzle width is defined as a narrowest point between the opposing protuberance and the opposing transverse end of the major island for each power nozzle, wherein a minor island spacing is defined as a shortest distance between the opposing transverse end of the minor island and the power nozzle associated therewith, and wherein the minor island spacing is less than double the power nozzle width.
9 . The fluidic insert of claim 1 wherein a floor formed on the major facing includes a stepped section between the inlet and the major island.
10 . The fluidic insert of claim 1 wherein fluid from the inlet flows around both of the transverse opposing ends the major island so as produce a pair of vortices within the interaction chamber and wherein the vortices alternate in strength so as to create an oscillating spray in the fluid that is ejected from the outlet.
11 . The fluidic insert of claim 1 wherein the exchange channel serves as an inertance loop that is alternatively fed by only one of the power nozzles so as to sustain an oscillating spray in the fluid that is ejected from the outlet.
12 . The fluidic insert of claim 1 wherein a bulbous depression is interposed between cach straight edge wall section and the protuberance associated therewith.